BIOTRONIK Evia DR, Техническое руководство

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Evia Technical Manual 87
7.13 Ventricular Capture Control (VCC)
7.13.1 Feature Description
The VCC feature periodically measures the capture threshold,
and automatically adjusts the pacing output (with a
programmable safety margin). Additionally, the feature
continuously assesses ventricular pacing capture on a beat-to-
beat basis and responds to any loss of capture with a safety
back-up pulse. During the clinical evaluation of the Ventricular
Capture Control algorithm, it was demonstrated that use of
Ventricular Capture Control can increase device longevity (as
compared to standard programming).
Differences in the signal morphology between the polarization
artifact and the evoked response signal are used to distinguish
capture events from non-capture events. The polarization
artifact is the signal caused by the pacing pulse between the
pacing electrode and the cardiac tissue. The evoked response
signal is the intracardiac signal measured during electrical
activation of the myocardium.
Figure 16
shows an example of an evoked response signal and
a polarization artifact. After an effective blanking period of
20 ms, the signal is evaluated over the next 60 ms. Several
characteristics of the signal falling into this window are evaluated
in order to discriminate the evoked response (capture) from
polarization artifact (possible non-capture).
Figure 16. Example of a Capture and a Non-Capture beat
Evoked Response
Polarization Artifact
Captur
Non-Capture